1. Field of the Invention
The present invention relates to a cap seal for a container such as a drum, particularly, relates to a cap seal for a container such as a drum that is provided with an RFID tag or the like, and more particularly, relates to a cap seal for internal and external double sealing of a container such as a drum, and a doubly-sealing apparatus of a container such as a drum using the same.
2. Description of the Background Art
Conventionally, for example, when a plug with a gasket is screwed into a fixed flange of a cap part of a drum, fitting and applying a cap seal to the metal part, the cap part is sealed.
The inventor of the present invention previously proposed a device described in Japanese Utility Model Application Publication No. 55-50119 as the above-described cap seal for a container such as a drum.
According to a tightly-sealing apparatus of a cap part of a drum using a cap seal, which is described in Japanese Utility Model Application Publication No. 55-50119, an annular convex part for engagement with a nail-shaped cross section is integrally provided on an inner surface of a lower end of a drooping wall of a cap seal made of a synthetic resin, which is formed by a circular top and the drooping wall formed on a peripheral border of the circular top, and this cap seal is fitted to the cap part of the drum from the above to cover the cap part. Thereby, a lower textile part of the drooping wall is brought into contact with the upper surface of a washer or the upper surface of a top panel with pressure with the inner upper edge part of the annual convex part for engagement brought into contact with the exterior convex part with pressure.
However, there is a problem such that double sealing of the cap part of the container such as the drum is not sufficient even if the cap seal described in Japanese Utility Model Application Publication No. 55-50119 is used.
Generally, a curling external diameter (the external diameter after a press flange is placed) of the cap part of the drum is not defined by Japanese Industrial Standards (JIS). Then, the curling external diameter of the press flange is about 69.88 to 68.8 mm in an actual dimension, so there is a difference about 1 mm.
On the other hand, the curling external diameter of the curling part of the apparatus for placing the press flange to the top panel of the drum has also a measurement difference. Depending on the shape of a curling piece, there is a difference about 4.0 to 5.0 mm. Further, a sheet thickness of a rising cylinder portion of the top panel (the attachment portion of the press flange) also has a difference about 0.8 to 1.6 mm, and a sheet thickness of a folding front end (a carling part) of the press flange also has a difference about 0.8 to 1.6 mm.
Due to these various errors, there is a problem such that the double sealing of the cap part of the container such as the drum by the cap sealing is not sufficient.
In addition, new tags including an RFID tag are developed in recent years, and by using these tags, logistics such as a quality control of a product, transportation control, control of entering and dispatching from warehouse, and position management is carried out, however, the logistics by applying these tags to the container such as the drum and its content has not been executed at the present step, so the realization of the logistics by using these tags has been strongly expected.